INDEX TO VOL. III. 



ACHROMATIC telescopes, 82. 



Adalbert, Prince, of Prussia, his 

 observations on the undulation 

 of the stars, 76. 



Alcor, a star of the constellation 

 Ursa Major, employed by the 

 Persians as a test of vision, 61, 

 272. 



Alcyone, one of the Pleiades, ima- 

 gined the centre of gravity of the 

 solar system by Madler, 269. 



Alphonsine tables, date of their 

 construction, 204. 



Anaxagoras of Clazomense, his the- 

 ory of the world-arranging intel- 

 ligence, 9 ; origin of the modern 

 theories of rotatory motion, 10. 



Andromeda's girdle, nebula in, 192. 



Arago, M., letters and communica- 

 tions of, to M. Humboldt, 57, 

 61, 87, 88, 96, 128, 282; on the 

 effect of telescopes on the visi- 

 bility of the stars, 88; on the 

 velocity of light, 106, 111; on 

 photometry, 123, 128; his cyano- 

 meter, 129. 



Aratus, a fragment of the work of 

 Hipparchus preserved in, 147. 



Archimedes, his " Arenarius," 35. 



Arcturus, true diameter of, 118. 



Argelander, his view of the number 

 of the fixed stars, 141 ; his addi- 

 tions to Bessel's catalogue, 155 ; 

 on periodically variable stars, 

 224. 



q Argus, changes in colour and 

 brilliancy of, 183, 241 



Aristotle, his distinct apprehension 

 of the unity of nature, 11 14; 

 his defective solution of the pro- 

 blem, 14 ; doubts the infinity of 

 space, 34 ; his idea of the genera- 

 tion of heat by the movement of 

 the spheres, 166. 



Astrognosy, th 1 * domain of the fixeJ 

 stars, 30. 



Astronomy, ;he observation of 

 groups of fixed stars, the first 

 step in, 158 ; very bright single 

 stars, the first named, 119. 



Atmosphere, limits of the, 49 ; 

 effects of an untransparent, 139. 



Augustine, St., cosmical views of, 

 167. 



Autolycus of Pitane, era of, 119. 



Auzout's object-glasses. 80. 



Bacon, Lord, the earliest views on 

 the velocity of light found in his 

 Novum Organum," 105. 



Baily, Francis, his revision of De 

 Lalande's Catalogue, 155. 



Bayer's lettering of the stars of any 

 constellation not an evidence of 

 their relative brightness, 132. 



Berard, Captain, on the change of 

 colour of the star y Crucis, 183. 



Berlin Academy, star-maps of the. 

 155. 



Bessel, on repulsive force, 41 ; his 

 star-maps have been the principal 

 means of the recognition of seven 

 new planets, 156 ; calculation of 

 the orbits of double stars by, 287. 



Binary stars, 271. 



Blue stars, 183 ; less frequent than 

 red, 285. 



Blue and green suns, the probable 

 cause of their colour, 283. 



Bond, of the Cambridge Observa- 

 tory, United States, his resolu- 

 tion of the nebula in Andro- 

 meda's girdle into small stars, 

 192. 



Brewster, Sir David, on the dark 

 lines of the prismatic spectra, 55. 



British Association, their edition af 

 Lalande's Catalogue, 155. 



2 



